Protective printing



j 4 j fnEnBEitTf EL Dow, CE MIDLANI),

yAssieivon `'ro THE now CHEMICAL PROTECTIVE' PRINTING.

' Application'iiled December 11, 1920." Serial No. 429,878.

` .rTo-aZZi/whom t mag/lconcemf 'i Be Vit knownthat I, HERBERT" H. l2oW,.a

citizenkof` the UnitedStates,Y and la resident uio `ofMidland, County of-Midlanchand State of ,.Michigan, have invented a. new and useful. Improvementin Protective Printing, of. 'y'fvhichil the following. isi a specification, the

yprinciple of the invention beingherein eX- plained andthe best inode in which lf lhave Ico"nteniplatedV .applying v that principle, so as to distinguish it from other inventions.

` The object of the present invention is the vproductionof aprinted article, such for example, as a postage or other stamp, greenback or evidence or value of anykind, that fwill vbefdiiiicult tofcounterfeit,fand that will v permit-the.i'eady'andjinstant'detectionv of a v Counterfeit *by one equipped ywith. proper f apparatus. .20"-

1: of .'thefstatedmeans hereinafter fully dev scribed and particularly pointed out in the claims, thefannexed drawingillustrating.but

Iseveral ofithefvarious ways'v in which Vthey l f principle' of the'invention may be carried Qf`0111; ..-y y

' sheet', beingshown as itl appears to the ordinary observer, i. e., to fthe. naked eye; Fig. 2

i l. similarto F ig. 2, but showing the eiifectthat may besecured where the impression consists 'offaf figure ordesign' insteadof al uniform color or groundwork.V f

' As indicated above, `the underlying.'prin-A diferentportions of the ligure or design with inks yhaving the samejcolor to thenaked eye' but possessing :different optical properties in anotherkrespect. v Thus', for example, one

lpor-tionmay be impressed with anink conj sist'ingofja single coloryand another portion impressed with an ,ink composedof aplural@y n. A y

.other portion thereof impressed with. an ink Vas such first-.named ink. i Malachite "green willfvserve'-asan illustration of such single l To the;accomplishmentfof the foregoing andrelated ends the invention .then consists v spectroscopie. y i i 4. A printed article having aigure or del 'sign impressed in one portion with an ink {colorand-obviouslyai-similarfshade of green I' l mayfbe'secured by mixing proper propor-k tions any ofthe known Ayellows and blues.

However, the effect of such different colors .or color combinations when viewed through MICHIGAN, COMPANY.

the case vofthe two'portions of such'fig'ure .n v

or design.

In the case of a solid green suchas shown in Figsl and 2, a portion of suchvground may be thus printed in a different color Com-j position or dye to show-the eect of a water mark Dow7 or'other name. Similarly, a figure 'suchas that vof an eagle as shown in Fig. 3 mayhave a portion in the form of a star printed in a different ink fromthe remainder so that when subjected to test such star willstand out.

thus used may be ones that appear diferent when j examined under a monochromatic light, or through a colorscreen.y

Other modes of applying the principle of The coloring matter employed inthe inks my invention may be employed instead of the one explained, change being made as re- J garde lthe method herein disclosed, kprovided the step or steps stated by any of the following claims or the equivalent .ofv such stated i yinkskhavingthe samecolor tothe naked eye 35"y illustrates the' same sheet whensuhjected to test vas.hf3reinafter described; F ig. 3 is a view.v

buil POSSGSSing dilierent optical properties in another respect.

2. A printed article having a figure or; de-

sign impressed in different` portions with inks havingthe saine color'to the naked eye 'but di'erent colors when viewed through a suitable optical instrument. :cipl'eof' the inventionPconsists-in printing y 3. A printed article fhaving a figure or design impressed in diiferent portions ywith inks havng'thesame color to the naked'ey'e but different 'colors when viewed through a* consisting of a single color` andv having ancomposed of a plurality of colors'givingthe same effect torthe eye as said first-named ink.y

HERBERT H.- Dow. 

